St. Johns County
Also known as Saint Johns County, St. Johns County, Florida, Saint Johns County, Florida, Saint John's County, St. John's County, St. Johns County, FL
county in Florida, United States
Key facts
- Country
- United States
- State
- Florida
- Founded
- July 21, 1821
- Named after
- San Juan del Puerto
- Seat
- St. Augustine
- Largest community
- St. Johns
- Total
- 822 sq mi (2,130 km )
- Land
- 601 sq mi (1,560 km )
- Water
- 221 sq mi (570 km ) 26.9%
- Estimate 2025
- 346,328
- Density
- 557/sq mi (215/km )
- Time zone
- UTC−5 ( Eastern )
- Summer dst
~12 min read
Article
St. Johns County is located in the northeastern part of the U.S. state of Florida. As of the 2020 United States census, its population was 273,425. The county seat and most populous incorporated city is St. Augustine, although the nearby community, St. Johns, has a higher population. St. Johns County is part of the Jacksonville, Florida Metropolitan Statistical Area.
The county was established in 1821. It is one of the two original counties established after Florida was ceded to the United States, at the start of the Florida Territorial period, and corresponded roughly to the former colonial province of East Florida. The other one It was named for the St. Johns River, which runs along its western border.